Sterilized multilayer film and method and apparatus for making the same

ABSTRACT

The present disclosure provides a sterilized multilayer film used for storing liquids and solids. The disclosure also provides an apparatus and method for producing a sterilized multilayer film appropriate for use in food and drink storage applications. In an example, the apparatus can produce a sterilized flexible storage bag for use in a container, for example, within a housing of the container, wherein a lid is positioned over an end of the housing, wherein the flexible storage bag is held between the lid and the housing.

BACKGROUND OF THE INVENTION

The present subject matter relates generally to a sterilized multilayer film for the packaging of food, medicine, and chemicals.

Typically, multilayer films used in packaging applications must be suitable for use in contact with the intended product such as foodstuff or medicinal product as required by the U.S. Food and Drug Administration. In addition, the multilayer film used in packaging must provide physical integrity to assure containment of the product and maintenance of the sterility, as well as the ability to be efficiently and safely processed by packaging machines. Further, the multilayer film must be able to be sterilized and be compatible with the method of sterilization used, e.g., heat, chemical, and/or radiation. In addition, the film should provide the greatest possible barrier protection against the transmission of gases (including oxygen) and moisture in order to achieve the longest possible shelf life with and/or without refrigeration.

In certain existing conventional methods, packaging film is unwound off a reel and fed through a sterilizing unit in which the film is sterilized by being moved through a relatively large immersion bath of highly concentrated aqueous hydrogen peroxide solution, which is heated in order to catalyze oxidation and thereby destroy putrefactive microorganisms. However, such processes, with movement through such a large high temperature bath of highly concentrated hydrogen peroxide solutions, are dangerous and costly, as the methods require extensive energy consumption, safety precautions against heat and toxic materials, and related equipment.

Accordingly, there is a need for a cost effective, safe, and environmentally friendly process for producing sterilized films. The cost and amount of the film components, and of materials and equipment used in sterilization, need to be reduced while maximizing the film's ease of processing, structural integrity and barrier against inward or outward transmission of gasses.

BRIEF SUMMARY OF THE INVENTION

The present disclosure provides a method and apparatus for producing sterile film with high ease of processing, structural integrity and barrier against gas transmission. Various examples of the film, apparatus, and method are provided herein.

The film is a multilayer film including a first layer, an intermediate layer, and a second layer, wherein the intermediate layer is positioned between the first layer and second layer. The first layer may include one or more layers of linear low density polyethylene (LLDPE), low density polyethylene (LDPE), other materials individually or collectively having similar moisture resistance, elasticity, and puncturability as that of polyethylene, and combinations thereof. The second layer may include one or more layers of LLDPE, LDPE other materials individually or collectively having similar moisture resistance, elasticity, and puncturability as that of polyethylene, and combinations thereof. The intermediate layer may include polyethylene-polyvinyl acetate (EVOH) and/or one or more other high gas barrier and low oxygen transmission rate polymers, or other organic or inorganic elements. In an example, additional layers of polyamide are positioned between the intermediate and the first layer, and between the intermediate layer and the second layer.

In an example, the disclosure provides a multilayer film comprising a first layer comprising a polyethylene polymer, wherein the thickness of the first layer is between, and including, 5 and 20 microns; a second layer comprising a polyethylene polymer, wherein the thickness of the first layer is between, and including, 15 and 60 microns; and an intermediate layer comprising ethylene vinyl alcohol, polyvinylidene chloride, polyvinylidene chloride co-methacrylate, polyvinylidene chloride co-acrylate, or combinations thereof, wherein the thickness of the intermediate layer is between, and including, 5 and 20 microns, wherein the intermediate layer is positioned between the first layer and the second layer.

The disclosure provides a flexible storage bag comprising a multilayer film comprising a first layer comprising a polyethylene polymer, wherein the thickness of the first layer is between, and including, 5 and 20 microns; a second layer comprising a polyethylene polymer, wherein the thickness of the first layer is between, and including, 15 and 60 microns; and an intermediate layer comprising ethylene vinyl alcohol, wherein the thickness of the intermediate layer is between, and including, 5 and 20 microns, wherein the intermediate layer is positioned between the first layer and the second layer, wherein the multilayer film forms the flexible storage bag, wherein an outer surface of the flexible storage bag is the first layer, and wherein an inner surface of the flexible storage bag is the second layer.

The method of manufacturing the multilayer film includes moving the multilayer film through a low concentration hydrogen peroxide bath, after which one or more wiper(s) may be applied to ensure an even and relatively thin distribution of the hydrogen peroxide across one or both of the surfaces of the multilayer film (e.g., wipers can be used on both sides of the bath, including front and back and up and down, wherein the wipers can independently, or in combination with an exit slot shaped for this purpose, prevent UVC light to enter the box and oxidize all or any of the hydrogen peroxide in the hydrogen peroxide bath). The multilayer film with the hydrogen peroxide coating is then subjected to UVC light and (optionally) hot air blower(s). The evenness and relative thinness of the surface coating of hydrogen peroxide speeds its oxidation, evaporation and residue removal, thereby enabling higher speed, and lower energy consumption, of the entire process. In an example, the method includes further processing the film, while remaining in a sterile aseptic environment, to form, fill, and seal a flexible storage bag.

In an example, the disclosure provides a method of manufacturing a sterile multilayer film, the method comprising advancing a multilayer film through a hydrogen peroxide solution bath, wherein the first layer and the second layer are coated with the hydrogen peroxide solution; wiping the first layer, and the second layer, to create a uniform thickness of the coating of hydrogen peroxide solution on the first layer and second layer; applying radiation from one or more UVC lights to the first layer and the second layer; and applying heated air to the multilayer film, wherein the temperature is between, and including, 15° C. to 70° C.

The apparatus used for sterilizing the multilayer film can include a propulsion system including multiple rollers that receives the multilayer film, and advances the film through an immersion chamber that is filled with aqueous hydrogen peroxide solution, which may be heated to temperatures that can be lower than 50° C. in order to provide a consistent chemical reaction throughout the production process regardless of the variations in the ambient temperatures. The immersion bath can have a depth as shallow as of 1 inch, and can have a width as narrow as is sufficient to enable passage of the film being immersed. The apparatus also can include at least one wiper that spreads and rapidly ensures an even and relatively thin distribution of hydrogen peroxide over the entire surface of the multilayer film. Alternatively, at least one roller can be applied to each coated surface of the film exiting the immersion chamber to serve the same purpose as the wiper, i.e., to rapidly ensure an even distribution of the hydrogen peroxide on the film, and remove any excess. The apparatus also includes one or more UVC light(s) applied to the film after exiting the immersion chamber and wiper or roller application. The apparatus can also include air blower(s) to be applied after and/or during the application of UVC light. The air blowers may blow room temperature or heated air and/or other gas(es) on the multilayer film.

In an example, the disclosure provides an apparatus for manufacturing a flexible storage bag, the apparatus comprising: a propulsion system for advancing a multilayer film; an immersion chamber configured to hold a hydrogen peroxide solution, wherein the immersion chamber is covered, wherein the film is moved through the solution held in the immersion chamber; and one or more UVC lights configured to apply UVC light to the multilayer film's coating of hydrogen peroxide solution, on the second layer and the first layer; wherein the propulsion system advances the multilayer film through the immersion chamber and to the UVC light.

In an example, the disclosed film may be used to house a liquid in a liquid container that is made predominantly from a paper housing, a thin rigid lid, and a single layer of shrink-wrap film, thereby resulting in a container that uses a majority of materials which are safely biodegradable under natural conditions, that uses zero non-recyclable materials, that can be easily separated into components that are recyclable in standard recycling facilities, and that can use up to 70% less plastic and non-recyclable materials than conventional plastic bottles. In addition to being environmentally friendly, the reduction in materials is also cost effective. In one example, the liquid container only uses 6.5 grams of plastic. In this example, the integrity, environmental friendliness and low cost of the container are enabled by the low cost, low gas transmission rate, and moderate elasticity and puncturability of the disclosed film.

An advantage of the present film and methods of manufacturing is enabling an increased shelf life of the content enclosed by the film, with reduced need for or no refrigeration.

A further advantage of the present films and methods, respectively, includes the lack of reliance on specialized, toxic, high-temperature or expensive sterilization, and safety equipment, wherein the present film can be made using conventional and inexpensive equipment.

Another advantage of the present films and methods, respectively, is providing a cost effective, moderate-temperature, non-toxic and otherwise safe process for producing sterilized films, which is safe to operate without expensive precautions against exposing human operators to the equipment's internal temperatures or chemical solutions.

Additional objects, advantages and novel features of the examples will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following description and the accompanying drawings or may be learned by production or operation of the examples. The objects and advantages of the concepts may be realized and attained by means of the methodologies, instrumentalities and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing figures depict one or more implementations in accord with the present concepts, by way of example only, not by way of limitations. In the figures, like reference numerals refer to the same or similar elements.

FIGS. 1A-1B is a cross-section of various embodiments of a multilayer film disclosed herein.

FIG. 2A is a perspective view of an embodiment of the apparatus used to sterilize the multilayer film disclosed herein.

FIG. 2B is a cross-sectional view of an embodiment of the apparatus used to sterilize the multilayer film disclosed herein.

FIG. 2C is a perspective view of an embodiment of the apparatus used to sterilize the multilayer film disclosed herein.

FIG. 2D is a perspective view of an embodiment of the immersion bath used to sterilize the multilayer film disclosed herein.

FIG. 2E is a partially exploded view of an embodiment of the immersion bath used to sterilize the multilayer film disclosed herein.

FIG. 3 is an exploded view of an example of a container incorporating the flexible storage bag disclosed herein.

FIG. 4 is a perspective view of an embodiment of the container disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure provides a multilayer film 2 including a first layer 4, an intermediate layer 6, and a second layer 8, wherein the intermediate layer 6 is positioned between the first layer 4 and second layer 8, as shown in FIG. 1A. The first layer may include one or more layers of polyethylene, such as, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), or combinations of both, or other materials or combinations having similar moisture resistance, gas transmission rate, elasticity and puncturability. The second layer may include one or more layers of polyethylene, such as LLDPE, LDPE, or combinations of both, or other materials or combinations having similar moisture resistance, gas transmission rate, elasticity and puncturability. An alternative first layer or second layer, having a substantially different gas transmission rate, may be substituted if the two layers, after being combined into a multilayer film, collectively have a similar gas transmission rate to that of the multilayer film comprising LLDPE and LDPE. Polyethylene is used in the first and second layer to enable the ability to seal together different portions or pieces of multilayer film into shapes such as a flexible storage bag. The incorporation of LLDPE in the first layer, second layer, or both, produces a multilayer film having higher tensile strength, higher impact resistance, slower transmission of liquids, and higher transparency. A further advantage of using LLDPE includes the ability to produce thinner films which enables improved UVC penetration, and resulting oxidation of hydrogen peroxide that is located on the film's surfaces, and/or that as penetrated into the film.

The intermediate layer 6 may include polyethylene-polyvinyl acetate, also known as ethylene vinyl alcohol copolymer (EVOH). EVAL™ can be used as the EVOH and is manufactured by Kuraray. Other suitable intermediate layers can include copolymers of vinylidene chloride (PVDC) such as PVDC-vinyl chloride or PVDC-methacrylate. In an example, an additional layer of polyamide 50 (e.g., nylon) is positioned between the intermediate layer 6 and the first layer 4, and between the intermediate layer 6 and the second layer 8, as shown in FIG. 1B.

Further, tie layers can be positioned between the first layer and the intermediate layer, and a tie layer can be positioned between the intermediate layer and the second layer. Any conventional tie layers can be used and typically do not contribute to the overall thickness of the multilayer films. A conventional tie layer includes incorporating functionality to the polyolefin, such as incorporating an anhydride functionality. For example, a tie layer can include maleic anhydride modified ethylene methacrylate polymers, and maleic anhydride modified ethylene vinyl acetate polymers. A specific example of an appropriate tie layer is AMPLIFY™ manufactured by Dow Chemical Company. The various layers can be coextruded or laminated together wherein the film surfaces are physically joined or bonded to each other by an adhesive lamination process or extrusion lamination process.

The disclosed materials used in each layer, the order of the layers, and the thicknesses of the layers have been selected to produce a multilayer film that is advantageous for sealing (e.g., a vertical seal and horizontal seal) the multilayer film into a sterilized flexible storage bag with physical integrity, and with minimal additional thickness. The thickness of the first layer may be between 5 and 20 microns. The thickness of the second layer may be between 15 and 60 microns.

When the flexible storage bag is used to store liquids, the first layer thickness can be less than the second layer thickness because the first layer forms the outer surface of flexible storage bag, wherein the second layer forms the inner surface of the flexible storage bag. In other words, the second layer is exposed to the content stored within the flexible storage bag. As a result, a thicker second layer provides improved plastic moisture barriers that decreases transmission of moisture. Because the first layer is typically thinner than the second layer for a flexible storage bag storing liquids, the weight and expense of the multilayer film is reduced. A thinner first layer is sufficiently thick to perform its functions because the first layer is not constantly exposed to moisture from the content of the flexible storage bag, in contrast to the second layer.

Alternatively, or additionally, the present films can be used in aseptic boxes (e.g., milk cartons) for storing juice, tea, dairy drinks, among others. Typically, in conventional aseptic and other three layer containers include, as the inner layer, a layer of only polyethylene, which has high gas permeability, consequently the containers must be stored in coolers and their shelf life is comparatively short. If the present film is incorporated in such aseptic containers, the shelf life will be drastically increased, which will lead to less waste, energy consumption and respectively more savings.

In yet another example, the present sterilized film can be used as a cover for single use plastic boxes for meals, meat, cheese, among other foods and liquids.

In an example where the multilayer film is used to house a liquid in a liquid container that is made predominantly from paper housing, the first layer's thickness may be further reduced while retaining sufficient thickness to prevent degradation, by externally originating radiation or contaminants, of the multilayer film's integrity, moisture resistance or gas barrier.

In contrast, when the flexible storage bag is used to store solid content (e.g., nuts, seeds, dried fruit, crackers, etc.) in many instances the oxygen transmission rate (OTR) requirements are not as high. As a result, thinner film layers can be used. For example, the first layer and second layer can independently have a thickness between 10 to 20 microns, and the intermediate layer can have a thickness as narrow as 5 microns.

The multilayer film thickness is typically less than 100 microns. In an example, when the multilayer film is used for a flexible storage bag for containing liquids, the thickness of the multilayer film can be between 40 to 85 microns. In an example, when the multilayer film is used for a flexible storage bag for storing dried food, the thickness can be 35 to 65 microns. The thickness deviation of each layer can be up to 3%, but not more than 1 micron. For example, a 10 micron layer can have a thickness deviation of ±0.3 microns. A 40 micron thick layer can have a thickness deviation of ±1 micron.

The intermediate layer may have a thickness of between 5 and 20 microns. Although, the more EVOH used in the intermediate layer the more expensive the product, and the less EVOH used in the intermediate layer results in a shorter shelf life owning to the higher oxygen transmission rate (OTR). The polyamide layers are optional. The inclusion of polyamide layers improves the strength of the multilayer film but can mildly increase the difficultly of puncturing the flexible storage bag made from the multilayer film.

In another embodiment, the first layer and/or second layer can be composed of an organic or other safely biodegradable material such as polylactic acid (PLA), wherein the intermediate layer can include EVOH or an organic or other safely biodegradable intermediate layer, such as shellac. An advantage of this embodiment is that the film can be organic, renewable, sustainable, and safely biodegradable.

The film can be folded and sealed to form a flexible storage bag for liquids and solids. For example, the flexible storage bag can be used to store liquid beverages, solid foods, and semisolid foods. Particularly advantageous is the ability of the disclosed multilayer film to be sealed with comparatively low heat and/or friction, and the lack of need for specialized, non-standard, high-cost or high-energy-using sealing equipment.

In an example, a sealing knife can be used to form a vertical seal to form the multilayered film into a tube. A sealing knife can be used to form a horizontal seal that forms a portion of the tube into an open bag. The bag can be filled with heated liquids, at a temperature within the range of 5° C. to 65° C., for example, within the range of 15° C. to 35° C. After the liquid is added into the open bag, a horizontal sealing knife is used to seal the top of the filled bag and at the same time to create the bottom of the next bag.

The method of manufacturing the multilayer film includes immersing the multilayer film briefly in a low concentration hydrogen peroxide bath, after which a wiper(s) or roller(s) may be applied to ensure a relatively even distribution of the hydrogen peroxide across one or both surfaces of the multilayer film. The concentration of hydrogen peroxide is typically between 1% and 5%, for example 3%. Because of the low concentration of hydrogen peroxide, the process is non-toxic and does not require special safety precautions such as breathing devices, gloves, goggles, etc., as compared with conventional methods of manufacture. Further, the amount of hydrogen peroxide solution used in the hydrogen peroxide bath is typically less than 1 liter, however the amount can depend on the thickness and width of the film and adjusted accordingly. Therefore, the low amount of hydrogen peroxide solution in combination with the low concentration of the hydrogen peroxide solution used in the present process provides a safer and less expensive process as large amounts of hydrogen peroxide are not required. In addition, the temperature of the hydrogen peroxide bath solution in the present process is below 50° C., as compared to existing processes that require higher temperatures that may be over 70° C. The disclosed method's moderate bath temperature has the function of facilitating, rather than catalyzing by itself, oxidation and evaporation of the hydrogen peroxide coating, from the film surface, and consequently is not necessary to maintain within a narrow range of deviation.

After the multilayer film with the hydrogen peroxide coating exits the bath, and being (optionally) subjected to the wiping/squeezing process, the multilayer film is then subjected to an ultraviolet light in the C spectrum (UVC light) that has a wavelength between 200-400 nanometers. One or more UVC lights irradiate the top surface of the multilayer film and (optionally, although unnecessary when the multilayer film is transparent) one or more additional UVC lights irradiate the bottom surface of the multilayer film. In order to prevent the UVC light from oxidizing the hydrogen peroxide in the hydrogen peroxide bath, the hydrogen peroxide bath is covered and a single entrance slot and a single exit slot of the bath chamber have just enough thickness to allow the multilayer film to enter and exit the bath. This minimal thickness may be achieved by fixing flexible blades or roller(s) (of silicon or other composition) along the top and bottom of the entry, exit or both slots. This flexibility enables the blades or rollers to be set in a position which would fully close the slots if no film was being fed between the slots, wherein during the continuous feeding of film through them during operation, to be pushed back by the film just far enough to enable film to feed through them.

After the UVC light has oxidized the hydrogen peroxide coating on the multilayer film, air blower(s) may be applied to the film to dry any remaining moisture on the multilayer film. Specifically, the air blower(s) may subject the film to air or other gas with a temperature of up to 70° C. in order to increase the speed and completeness of evaporating any remaining moisture after UVC light application, and removing any remaining hydrogen peroxide residue. The evenness and relative thinness of the surface coating of hydrogen peroxide (optionally improved by the wiping and/or squeezing process) speeds the coating's oxidation, evaporation and residue removal, thereby enabling higher speed, and lower energy consumption, of the entire process.

In the example where the multilayer film is used to make a flexible storage bag to house a liquid in a liquid container that is made predominantly from a paper housing and a lid, the total thickness of the film must not have so much tackiness as to prevent the corners of the flexible storage bag from protruding, but must have sufficient tackiness to create friction with the lid lip and then paperboard housing edge when the flexible storage bag corners are folded over both sides of the edge and, together with that edge, are pinched inside the lid lip. Further, for flexible storage bags which consumers are intended to puncture with (and drink through) a straw, the film's puncturability by the tip of a straw is balanced against the film's resistance to other damage. Further, upon the straw creating a hole in the film, the edge of the hole clings to the circumference of the straw closely enough to prevent exit of liquid, and to minimize passage of air, when the bag is squeezed, but does not cling so tightly as to prevent the straw from sliding through the hole in order to reach deeply into the bag.

In the example where the multilayer film is used to make a flexible storage bag, the multilayer film is folded lengthwise sealing the film into a tube, and then receives a single horizontal seal which forms a section of the tube into an open bag, in order to receive injection of the product content, e.g., a liquid product. In an example, the added liquid can be pasteurized or otherwise heated. After injection of the product into the tube, the multilayer film receives a second horizontal seal which closes the top of the bag and fully seals the product within the flexible storage bag. In an example where multiple bags are formed from a tube in a continuous process, the second horizontal seal closing the top of one bag can simultaneously be the first horizontal seal creating the next bag.

As a result of the disclosed film and method, a sterilized flexible storage bag may be produced that prevents transmission of gasses into or out of the flexible storage bag thereby increasing the shelf life of the product stored within the flexible storage bag. The flexible storage bag can withstand, without bursting or leaking, the impact of falling onto a hard surface from a height of at least 1.5 meters, and being squeezed by a weight of at least 15 kg. The portion of the flexible storage bag, through which a consumer is intended to insert a straw, has sufficient integrity to be exposed directly to the external environment, although an additional external layer, which may be of shrink-wrap film, may be added in order to prevent external contaminants from touching the flexible storage bag. The oxygen transmission rate is improved drastically as compared to standard polyethylene film, further improving cost and shelf life of the content of the flexible storage bag.

The film is typically transparent to permit additional, secondary processing with UVC light on both the inside and outside surfaces of the film as well as the contents of the flexible storage bag.

As shown in FIGS. 2A-2E, the apparatus 60 used for the sterilizing of the multilayer film 62 can include a multi-roller system 64 including multiple rollers that receives the multilayer film 62 and advances the film through an immersion chamber 66. As shown in FIGS. 2D-2E, the immersion chamber 66 can include a covered shallow tray that is filled with a hydrogen peroxide solution. The immersion chamber 16 can have a depth as little as 1 inch, which can be adjustable. The sides of the immersion chamber are closed except for an opening 68 to allow the multilayer film to enter and exit. Because the sides are closed, the UVC light 70 does not oxidize the hydrogen peroxide in the hydrogen peroxide bath. The apparatus can also include a wiper(s) 72 or roller(s) that ensures an even and relatively thin distribution of hydrogen peroxide over the entire surface of the multilayer film. In an example, the system can include four to eight wipers. The film's surface immersion in hydrogen peroxide solution, and subsequent wiping, facilitates standardization depth of the hydrogen peroxide coating without beading of the solution. The apparatus includes a UVC light 70 applied after the wiper application to sterilize the multilayer film. In addition, the apparatus can include blower(s) 74 of air or other gas, which may be heated, to dry the film and remove any residue. In an example, the apparatus can include a sealing system to fold and seal the multilayer film into the flexible storage bag 20.

As shown in FIGS. 3-4, the flexible storage bag can be incorporated in an eco-friendly container for liquids and/or solids, wherein the container components, including the size and shape of the components, are intended to minimize the material and transportation cost for both the materials to make the containers and the final container product. The container 10 also typically does not include permanent bonding or adhesives between items that need to be separated for recycling and, therefore, after the container is used can be easily separated in order to simplify and encourage consumer cooperation with recycling. As such, the container 10 may easily use standard waste collection channels and can fully utilize existing recycling systems.

In an embodiment, the container 10 includes a housing 12 including a side wall 14, a housing first end 16, and a housing second end 18, as shown in FIGS. 3-4. The housing 12 may be made of any suitable material, though the advantages provided herein are best accomplished using a recyclable and biodegradable product. For example, the housing 12 may be made of a foldable cardboard, sugarcane pulp, corn pulp, combinations thereof, or any other paper product. Alternatively, the housing 12 may be made from thin plastic, aluminum, etc.

The housing 12 may be formed by folding the housing material from a flat configuration into a three-dimensional shape. For example, the housing 12 may be formed by folding a single sheet of paper into a cylindrical shape or any of various cross-sectional shapes. For example, the housing 12 may be a circular, triangular, rectangular, hexagonal, octagonal or other cylinder. The three-dimensional housing 12 may be stabilized using a minimal amount of adhesive or, in certain circumstances, without adhesive.

The container 10 can enclose the flexible storage bag 20 within the housing 12. The flexible storage bag 20 may be any suitable size. For example, the flexible storage bag 20 may be capable of holding 8 ounces (oz.), 12 oz., 16 oz., 20 oz., or 24 oz., among other amounts. Similarly, the housing 12 may be various sizes and shapes. Further, it should be understood that the term “liquid” is meant to encompass various substances with varying viscosities, typically viscosities that may pass through a straw 30. For example, in this disclosure the term “liquid” includes, but is not limited to, water, non-carbonated drinks, sport drinks, energy drinks, smoothies, baby food, pureed food, soups, milk, milk shakes, coffee drinks, tea, juice, salad dressing, gravy, broth, and condiments, such as ketchup, mustard, mayonnaise, among others.

The container 10 can also include a lid 22 positioned over the housing first end 16, wherein at least a portion of the flexible storage bag 20 is held between the lid 22 and the housing first end 16, as shown in FIG. 2B. In an example, at least two portions of the flexible storage bag 20 are secured between the lid 22 and the housing first end 16. The lid 22 may be made of any suitable material. Typically, the lid 22 is made of a thin, plastic material.

In addition, the container 10 includes a shrink-wrap film 24 surrounding at least a portion of the housing 12 and at least a portion of the lid 22, wherein the shrink-wrap film 24 secures the lid 22 to the housing 12. The shrink-wrap film 24 assists to secure the lid 22 and flexible storage bag 20 to the housing 12 without the use of adhesives or other connecting mechanism, such as tape, glue, clips, or fasteners, among others. Because the container 10 does not use adhesives to secure various elements together, the container may be easily sorted into established recyclable products after the container is used. For example, once the shrink-wrap film 24 is removed, the lid 22, the flexible storage bag 20, and the housing 12 can be easily detached, thereby allowing the various elements to be easily sorted for recycling. For example, the shrink-wrap film 24, lid 22, and flexible storage bag 20 may be recycled in a plastic receptacle, whereas the housing 12 may be recycled in a paper receptacle, with minimal effort required to separate the various elements.

EXAMPLES

Various multilayer films were produced as indicated in Table 1. The layer thicknesses (reported in microns) for the examples are shown in Table 1.

For example, Example 1 is a multilayer film including a first layer of LLDPE, a second layer of LLDPE, and an intermediate layer of EVOH. A first polyamide layer is positioned between the first layer and intermediate layer. A second polyamide layer is also positioned between the intermediate layer and the second layer. Further, tie layers are positioned between the first layer and first polyamide layer, the first polyamide layer and the intermediate layer, the intermediate layer and the second polyamide layer, and the second polyamide layer and the second layer.

In contrast, Example 4 is a three layer film including LLDPE for both the first layer and second layer, and an intermediate layer of EVOH positioned between the first layer and second layer.

TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 LLDPE 7.75  15.5  7.5 15   7.5 15   7.5 15 LLDPE 7.75 —  7.5 —   7.5 —   7.5 — Tie 0 — 0  — 0 —  0 — PA 2 2 — — — — — — Tie 0 — — — — — — — EVOH 5 5 10   10 5  5 10 10 Tie 0 — 0  — 0 —  0 — PA 2 2 — — — — — — Tie 0 — — — — — — — LLDPE 17.5 — 17.5 — 20  — 20 — LLDPE 17.5  35.5 17.5 35 20  40 20 40

Examples 1-8 all demonstrated a fluctuation of 2.5%.

It should be noted that various changes and modifications to the embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. For example, various embodiments of the method may be provided based on various combinations of the features and functions from the subject matter provided herein. 

1. (canceled)
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 5. A flexible storage bag container comprising: a multilayer film comprising a first layer comprising a polyethylene polymer, wherein the thickness of the first layer is between, and including, 5 and 20 microns, a second layer comprising a polyethylene polymer, wherein the thickness of the first layer is between, and including, 15 and 60 microns, and an intermediate layer comprising ethylene vinyl alcohol, polyvinylidene chloride, polyvinylidene chloride co-methacrylate, polyvinylidene chloride co-acrylate, or combinations thereof, wherein the thickness of the intermediate layer is between, and including, 5 and 20 microns, wherein the intermediate layer is positioned between the first layer and the second layer, wherein the multilayer film forms the flexible storage bag, wherein an outer surface of the flexible storage bag is the first layer, and wherein an inner surface of the flexible storage bag is the second layer; and a housing including a side wall, a housing first end, and a housing second end, wherein the flexible storage bag is positioned within the housing; and a lid positioned over the housing first end, wherein at least a portion of the flexible storage bag may be held between the lid and the housing first end.
 6. The flexible storage bag container of claim 5, wherein the first layer includes linear low density polyethylene, and the second layer includes linear low density polyethylene.
 7. The flexible storage bag container of claim 5, wherein the first layer includes at least two layers of linear low density polyethylene, and where the second layer includes at least two layers of linear low density polyethylene.
 8. The flexible storage bag container of claim 5, further comprising a first polyamide layer between the first layer and the intermediate layer, and a second polyamide layer between the intermediate layer and the second layer.
 9. The flexible storage bag container of claim 5 further comprising a shrink-wrap film surrounding at least a portion of the housing and at least a portion of the lid, wherein the shrink-wrap film secures the lid to the housing.
 10. A method of manufacturing a sterile multilayer film, the method comprising: advancing a multilayer film through a hydrogen peroxide solution bath, wherein the first layer and the second layer are coated with the hydrogen peroxide solution; and applying radiation from one or more UVC lights to the first layer and the second layer.
 11. The method of claim 10 further comprising wiping each coated layer to create a uniform thickness of the coating of hydrogen peroxide solution.
 12. The method of claim 10 further comprising applying blown gas to the multilayer film after the multilayer film exits the hydrogen peroxide solution bath, wherein the temperature of the air does not exceed 70° C.
 13. The method of claim 10 further comprising sealing the multilayer film to form the flexible storage bag, wherein an outer surface of the flexible storage bag is the first layer, and wherein an inner surface of the flexible storage bag is the second layer.
 14. The method of claim 10, wherein the multilayer film includes a first layer comprising a polyethylene polymer, wherein the thickness of the first layer is between, and including, 5 and 20 microns; a second layer comprising a polyethylene polymer, wherein the thickness of the first layer is between, and including, 15 and 60 microns; and an intermediate layer comprising ethylene vinyl alcohol, polyvinylidene chloride, polyvinylidene chloride co-methacrylate, polyvinylidene chloride co-acrylate, or combinations thereof, wherein the thickness of the intermediate layer is between, and including, 5 and 20 microns, wherein the intermediate layer is positioned between the first layer and the second layer.
 15. An apparatus for manufacturing a flexible storage bag, the apparatus comprising: a propulsion system for advancing a multilayer film, wherein the multilayer film includes a first layer and a second layer; an immersion chamber configured to hold a hydrogen peroxide solution, wherein the immersion chamber is covered, wherein the multilayer film is moved through the solution held in the immersion chamber; and one or more UVC lights configured to apply UVC light to the first layer and the second layer of the multilayer film, wherein the propulsion system advances the multilayer film through the immersion chamber and to the UVC light.
 16. The apparatus of claim 15 further comprising one or more wipers configured to wipe a coating of hydrogen peroxide solution on the multilayer film to create a uniform thickness of the hydrogen peroxide solution on the multilayer film as the multilayer film exits from the immersion chamber.
 17. The apparatus of claim 15 further comprising one or more wipers configured to wipe a coating of hydrogen peroxide solution on the multilayer film to create a uniform thickness of the hydrogen peroxide solution on the multilayer film after the multilayer film exits from the immersion chamber.
 18. The apparatus of claim 15 further comprising one or more blowers configured to apply gas to the multilayer film, wherein the temperature of the gas does not exceed 70° C., wherein the blowers apply the gas to the multilayer film after the multilayer film exits the immersion chamber.
 19. The apparatus of claim 15, wherein the propulsion system includes a plurality of rollers. 